A sensor translates a change in an external stimulus into a change in a detectable or measurable sensed parameter. In various implementations, sensors may be formed using passive electronic devices, such as inductors, capacitors and/or resistors. The circuit value of these sensors (e.g., inductance, capacitance, or resistance value) varies with a parameter of interest. These sensors may be incorporated into a sensor circuit so that the variation of the circuit value caused by the changing parameter of interest alters the sensor circuit output.
It is often desirable to remotely acquire sensor information. Radio frequency identification (RFID) circuitry has been used to detect the presence and movement of articles of interest. The remote access capabilities of RFID technology may be combined with sensor technology to provide remote sensing capability. The present invention fulfills these and other needs, and offers other advantages over the prior art.